Screening for Diabetes after Pregnancy

The Women’s Preventive Services Initiative (WPSI) recommends screening for type 2 diabetes in women with a history of gestational diabetes mellitus (GDM) who are not currently pregnant and who have not previously been diagnosed with type 2 diabetes. Initial testing should ideally occur within the first year postpartum and can be conducted as early as 4–6 weeks postpartum.

Women who were not screened in the first year postpartum or those with a negative initial postpartum screening test result should be screened at least every 3 years for a minimum of 10 years after pregnancy. For those with a positive screening test result in the early postpartum period, testing should be repeated at least 6 months postpartum to confirm the diagnosis of diabetes regardless of the type of initial test (eg, fasting plasma glucose, hemoglobin A_1C, oral glucose tolerance test). Repeat testing is also indicated for women screened with hemoglobin A_1C in the first 6 months postpartum regardless of whether the test results are positive or negative because the hemoglobin A_1C test is less accurate during the first 6 months postpartum.

In addition to the follow-up screening for women with a history of GDM recommended above, the WPSI recommends adherence to diabetes screening guidelines for the general population. Guidelines for general population screening are available from the U.S. Preventive Services Task Force and American Diabetes Association.

Postpartum follow-up visits are recommended after delivery, with the initial assessment ideally within 3 weeks, a comprehensive postpartum visit by 12 weeks, and care continuing through the first year after birth. These visits provide an opportunity for screening for type 2 diabetes after GDM, especially for patients with limited access to health care after pregnancy. The WPSI recommends that postpartum visits include a discussion of future diabetes screening for women with history of GDM. Ongoing care with a primary care clinician is important to facilitate appropriate diabetes screening and prevention counseling after pregnancy.

Compared with other tests, hemoglobin A_1C is less accurate in the first months after pregnancy and may be inaccurate in women with conditions such as anemia, renal failure, or certain hemoglobinopathies (eg, thalassemia and sickle cell disease or trait), or who have had a recent transfusion. However, given the low rates of postpartum testing with fasting plasma glucose and oral glucose tolerance tests, hemoglobin A_1C may be considered when other tests are not feasible. By 6 months postpartum, the physiologic changes related to pregnancy have usually resolved; therefore, all standard screening tests are accurate after 6 months.

• Research evaluating the benefits and harms of screening for type 2 diabetes after gestational diabetes.
• Studies to identify tests or protocols that improve the accuracy of detecting type 2 diabetes in the immediate postpartum period, increase compliance with screening, and determine the optimal timing of diabetes testing after pregnancy. This includes research to evaluate the accuracy of random glucose tests and determine when hemoglobin A_1C becomes a reliable screening test after pregnancy.
• Studies that measure the impact of weight changes, anemia correction, and lactation on diabetes screening test results.
• Research that evaluates GDM prevention strategies and programs including approaches to reduce barriers to screening.
• Studies that evaluate women with a history of GDM with initial negative screening test results after pregnancy and identify appropriate counseling strategies, determine the optimal time frame for follow-up screening, and identify predictors for the development of subsequent type 2 diabetes and related long-term outcomes, such as cardiovascular disease.